Nemo's Lodge is in Fortuneswell on Portland. It's a three bedroom house, sleeps six, one bathroom. It's got a 3 Star rating. That means it's functional and clean. It's not a show home.
You can bring one dog. There's a small patio garden out the back and parking for one car on the drive.
The house is in the village, so you can walk to the local shop and the pub. The pub does food. Chesil Beach is very close, just down the hill. It's not a sandy beach, it's all pebbles. The sea is cold.
Portland Bill is about three miles south. Good for walking and watching the boats. Portland Castle is about a fifteen minute drive. Weymouth is over the bridge, maybe twenty minutes by car depending on traffic. That's where you find the sandy beach, the big seafront, and more shops.
For a day out, you can drive to Lulworth Cove or Durdle Door in under half an hour. The tank museum at Bovington is about the same.
Inside, it's got what you'd need: a washing machine, dishwasher, WiFi, TV. All the bedding and towels are included. The kitchen has the basics.
Useful links: Dorset Council Jurassic Coast and National Trust Jurassic Coast.